From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: Re: [PATCH 1/5] bonding: simplify and use RCU protection for 3ad xmit path Date: Fri, 30 Aug 2013 09:57:04 +0800 Message-ID: <521FFBF0.8040107@huawei.com> References: <521D7A96.9070904@huawei.com> <521F59E2.8030707@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Jay Vosburgh , Andy Gospodarek , "David S. Miller" , Veaceslav Falico , Netdev To: Nikolay Aleksandrov Return-path: Received: from szxga02-in.huawei.com ([119.145.14.65]:31121 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754948Ab3H3B5e (ORCPT ); Thu, 29 Aug 2013 21:57:34 -0400 In-Reply-To: <521F59E2.8030707@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2013/8/29 22:25, Nikolay Aleksandrov wrote: > On 08/28/2013 06:20 AM, Ding Tianhong wrote: >> The commit 278b20837511776dc9d5f6ee1c7fabd5479838bb >> (bonding: initial RCU conversion) has convert the roundrobin, active-backup, >> broadcast and xor xmit path to rcu protection, the performance will be better >> for these mode, so this time, convert xmit path for 3ad mode. >> >> Signed-off-by: Ding Tianhong >> Signed-off-by: Wang Yufen >> Cc: Nikolay Aleksandrov >> Cc: Veaceslav Falico >> --- >> drivers/net/bonding/bond_3ad.c | 31 +++++++++++++------------------ >> drivers/net/bonding/bonding.h | 22 ++++++++++++++++++++++ >> 2 files changed, 35 insertions(+), 18 deletions(-) >> >> diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c >> index 9010265..52d76a4 100644 >> --- a/drivers/net/bonding/bond_3ad.c >> +++ b/drivers/net/bonding/bond_3ad.c >> @@ -143,7 +143,7 @@ static inline struct bonding *__get_bond_by_port(struct port *port) >> */ >> static inline struct port *__get_first_port(struct bonding *bond) >> { >> - struct slave *first_slave = bond_first_slave(bond); >> + struct slave *first_slave = bond_first_slave_rcu(bond); >> >> return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL; >> } >> @@ -163,7 +163,7 @@ static inline struct port *__get_next_port(struct port *port) >> // If there's no bond for this port, or this is the last slave >> if (bond == NULL) >> return NULL; >> - slave_next = bond_next_slave(bond, slave); >> + slave_next = bond_next_slave_rcu(bond, slave); >> if (!slave_next || bond_is_first_slave(bond, slave_next)) >> return NULL; >> >> @@ -2417,16 +2417,14 @@ int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info) >> >> int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) >> { >> - struct slave *slave, *start_at; >> + struct slave *slave; > Please re-arrange longest -> shortest where possible. > something wrong with my vim, so fix it, thanks. >> struct bonding *bond = netdev_priv(dev); >> int slave_agg_no; >> int slaves_in_agg; >> int agg_id; >> - int i; >> struct ad_info ad_info; >> int res = 1; >> >> - read_lock(&bond->lock); >> if (__bond_3ad_get_active_agg_info(bond, &ad_info)) { >> pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n", >> dev->name); >> @@ -2444,13 +2442,16 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) >> >> slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg); >> >> - bond_for_each_slave(bond, slave) { >> + bond_for_each_slave_rcu(bond, slave) { >> struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator; >> >> if (agg && (agg->aggregator_identifier == agg_id)) { >> - slave_agg_no--; >> - if (slave_agg_no < 0) >> - break; >> + if (--slave_agg_no < 0) { >> + if (SLAVE_IS_OK(slave)) { >> + res = bond_dev_queue_xmit(bond, skb, slave->dev); >> + goto out; >> + } >> + } >> } >> } >> >> @@ -2460,23 +2461,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev) >> goto out; >> } >> >> - start_at = slave; >> - >> - bond_for_each_slave_from(bond, slave, i, start_at) { >> - int slave_agg_id = 0; >> + bond_for_each_slave_rcu(bond, slave) { >> struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator; >> >> - if (agg) >> - slave_agg_id = agg->aggregator_identifier; >> - >> - if (SLAVE_IS_OK(slave) && agg && (slave_agg_id == agg_id)) { >> + if (SLAVE_IS_OK(slave) && agg && >> + (agg->aggregator_identifier == agg_id)) { > Please drop the ( ) from (agg->aggregator_identifier == agg_id), also align it > properly. > my mistake, thanks. >> res = bond_dev_queue_xmit(bond, skb, slave->dev); >> break; >> } >> } >> >> out: >> - read_unlock(&bond->lock); >> if (res) { >> /* no suitable interface, frame not sent */ >> kfree_skb(skb); >> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h >> index 4bf52d5..ecb5d1d 100644 >> --- a/drivers/net/bonding/bonding.h >> +++ b/drivers/net/bonding/bonding.h >> @@ -74,6 +74,9 @@ >> /* slave list primitives */ >> #define bond_to_slave(ptr) list_entry(ptr, struct slave, list) >> >> +/* slave list primitives, Caller must hold rcu_read_lock */ >> +#define bond_to_slave_rcu(ptr) list_entry_rcu(ptr, struct slave, list) >> + >> /* IMPORTANT: bond_first/last_slave can return NULL in case of an empty list */ >> #define bond_first_slave(bond) \ >> list_first_entry_or_null(&(bond)->slave_list, struct slave, list) >> @@ -81,6 +84,16 @@ >> (list_empty(&(bond)->slave_list) ? NULL : \ >> bond_to_slave((bond)->slave_list.prev)) >> >> +/** >> + * IMPORTANT: bond_first/last_slave_rcu can return NULL in case of an empty list >> + * Caller must hold rcu_read_lock >> + */ > Styling nit: the comments in net/ should be /* text... miss the net-next. add in resend. > >> +#define bond_first_slave_rcu(bond) \ >> + list_first_or_null_rcu(&(bond)->slave_list, struct slave, list) >> +#define bond_last_slave_rcu(bond) \ >> + (list_emptry(&(bond)->slave_list) ? NULL : \ > ^^^^^^^^^^^^^^^^^^^^^ > Did you compile this ? oh, I compiled, but the func did not used, so did not show any problem, it's a big error, I will review and check all above. > >> + bond_to_slave_rcu((bond)->slave_list.prev)) >> + >> #define bond_is_first_slave(bond, pos) ((pos)->list.prev == &(bond)->slave_list) >> #define bond_is_last_slave(bond, pos) ((pos)->list.next == &(bond)->slave_list) >> >> @@ -93,6 +106,15 @@ >> (bond_is_first_slave(bond, pos) ? bond_last_slave(bond) : \ >> bond_to_slave((pos)->list.prev)) >> >> +/* Since bond_first/last_slave_rcu can return NULL, these can return NULL too */ >> +#define bond_next_slave_rcu(bond, pos) \ >> + (bond_is_last_slave(bond, pos) ? bond_first_slave_rcu(bond) : \ >> + bond_to_slave_rcu((pos)->list.next)) >> + >> +#define bond_prev_slave_rcu(bond, pos) \ >> + (bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \ >> + bond_to_slave_rcu((pos)->list.prev)) >> + >> /** >> * bond_for_each_slave_from - iterate the slaves list from a starting point >> * @bond: the bond holding this list. >> > > > . >